We propose to study in detail the formation of computed NMR images and to apply realtime video computational techniques to them to allow the synthesis of NMR images made with arbitrary pulse sequences. It is expected that such methods may allow some reduction in the time of NMR data acquisition and will substantially reduce the time of NMR image analysis. Computed images of the three basic quantities in proton imaging will be studied: spin-lattice relaxation time T1, spin-spin relaxation time T2, and proton density. Once determined, the computed images will be passed through the various exponential equations describing the commonly used pulse sequences. By generating these equations with hardwired realtime circuitry and allowing such parameters as pulse delay time and repetition time to be variable, it will be possible to synthesize NMR images in "realtime." That is, after interactive adjustment of a pulse parameter, the corresponding synthesized image will appear on a television monitor 1/30 sec. later. This technique offers the promise of retrospective maximization of contrast between arbitrary materials after a single NMR acquisition. Specific aims of this project are: 1. Optimization of the determination of computed T1, T2, and Mo images. 2. Study of the validity and limitations of the use of computed NMR images for image synthesis. 3. Construction of a dedicated electronic digital video processor for realtime synthesis of NMR images. 4. Evaluation of the limitations and utility of automated NMR image synthesis with initial clinical studies.